'Last fall, Senator Mitch McConnell said that if Buffett was feeling “guilty” about paying too little in taxes, he should “send in a check.”'<p>'So, Buffett has pledged to match one for one all such voluntary contributions made by Republican members of Congress. “And, I’ll even go three for one for McConnell.” That could be quite a bill if McConnell takes the challenge; after all, the Senator is worth at least $10 million. As Buffett put it to me: “I’m not worried.”'